This research would seek a basis for more effective chemotherapy of patients with malignant intracranial neoplasms primarily through systematic studies on their experimental biology. The behavior of these neoplasms, especially the gliomas, would be defined further by cellular and subcellular studies in cell cultures. Chemotherapy studies in vitro would be advanced from static observations on morphologic alterations to analysis of drug effects on cell kinetics, biochemical mechanisms and enzymatic properties in primary and cloned cell lines. Immunological aspects, the possible role of viral neuro-oncogenesis, the heterotransplantation of human gliomas, and further analysis of the oncolytic potential and mechanisms of steroids are some other facets of this research program. The efficacy of steroids and some newer chemotherapeutic drugs will be evaluated in limited clinical trials along with a plan of chemotherapy for recurrent medulloblastomas.